Vol. 11 No. 5 (2013)

A total of 22 new combinations of hybrid tomato were tested in 2011 autumn – winter (12 combinations) and 2012 Spring-Summer cropping season (10 combinations) at four locations in three provinces: Hai Phong, Thai Binh and Nam Dinh. Four hybrid combinations , T10, T12, T18 and T19 performed best in 2011 autumn – winter season and other four hybrid combinations, T12, T16, T19 and T26 showed high yield and low viral disease incidence in 2012 spring-summer season.

Early flowering is undesirable in tobacco (Nicotiana tabacumL.) production because it reduces yield and quality of raw materials. This study was carried out to determine the possibility of delaying floral induction and flowering without causing undesirable side-effects to the plants. Flue-cured tobacco plants of cultivar K326 were treated with various combinations day length and night break lighting under nethouse conditions. Four hours supplemental lighting (prolong day length duration, equivalent to 16hours/8hours day/night) and one-hour middle-of-night interruption were able to delay flower induction/flowering of the short - day tobacco plants cv. K326. Detopping of plants under field conditions to induce new branch also prolonged days to flowering. If night interruption or supplemental lighting was implemented continuously for 10 or more cycles, flowering could be delayed by 28 to 30days. Detopping to promote branching at 5th and 10thleaf position delayed flowering by 8 days and yielded in increased leaf number and size in comparison with the control.

The biological characteristics of sesame leaf roller Antigastra catalaunalis (Duponchel) was studied on Sesamum indicum (L.) local variety (black seed) under laboratory and field condition during August, September 2012. The research results shown that, pre-adult period about 2-5 days. There were five larval instars. Developmental period is rather short (egg, larva, pupa, adult pre-oviposition was 3.04, 11.54, 4.65 and 3.38 days respectively. Average life cycle’s 22,28±3,16 days at condition of average temperature and humidity of 29.2oC and 75.1%.The life span and oviposition capacity of the adult was 2-9 days and laid about 62.8-116.0 eggs/female depends on food supplement. Mean of egg hatching ratio 83%. Adult emergence ratio was 88.4% from those reared in lab. condition to 91.0% from the individuals collected from field. Sex ratio was about 48.3-48.6% male and 51.4-51.7% female.

The study was conducted in net house to investigate the interactive effects of sandy soil amendment with biochar and foliar fertilizer on growth and yield of tomato. The experiment arranged in a Completely Randomized Design- CRD included three biochar levels (amendment 1%, 3% or unamended) and four kinds of foliar fertilizer with three replications were used. The result showed that biochar had significant effect on plant hight and leaves of tomato whereas foliar fertilizer did not affect on those of tomato. The interaction of biochar and foliar fertilizer increased significantly the number of fruits, individual fruit weight and yield of tomato grown on sandy soil. The individual yield of tomato was climbed by biochar amendment and supplement foliar fertilizer from 23.6% to 39.8% and from 43.0% to 66.8% respectively.

Nghiên cứu tính đa hình của exon 14, gen Mx được thực hiện trên 7 giống gà bản địa của Việt Nam (bao gồm: gà Ác, Đông Tảo, H’Mông, Hồ, Mia, Móng và Ri). Kết quả cho thấy tính đa hình của exon 14 xảy ra tại hai vị trí (2032 và 2159). Sự thay thế A hoặc G tại vị trí 2032 của gen Mx có ở tất cả 7 giống gà bản địa được sử dụng trong nghiên cứu này. Trong cùng một giống đều có cả hai alen A và G, tuy nhiên, alen A (liên quan đến tinh kháng virus) có tần số xuất hiện cao hơn so với alen G (liên quan đến tính mẫn cảm với virus). Đặc biệt, tần số của alen A ở giống gà Ri và gà H'mong là cao nhất trong số 7 giống được kiểm tra (với tỉ lệ tương ứng là 80,91% và 74,04%). Phân tích so sánh các axit amin cho thấy sự thay đổi nucleotide A hoặc G tại vị trí 2032 sẽ dẫn đến sự thay đổi axit amin tại vị trí 631 của protein Mx từ Asparagine (liên quan tới khả năng kháng virus của giống) sang Serine (không liên quan tới khả năng kháng virus của giống).

The study on effects of temperature and salinity on embryonic development, hatching rate of mouse grouper (Cromileptes altivelis) were designed to identify optimal temperature and salinity for incubation ofCromileptes altivelis eggs. The fertilization eggs were incubated in a series of 1L-glass beakers at a density of 100 eggs/L in two separated experiments. The first experiment was conducted at five different temperature treatments at 20, 24, 28, 32 and 36ºC at 29‰ with three replicates for each. The second pilot incubates eggs at 28.0 ± 1.0ºC in different salinity treatments of 23, 26, 29, 32 and 35‰. The results from the temperature experiment showed that eggs incubated at 28oC for the highest hatching rate (87.4 ± 3.3%) and lowest deformity rate (4.8 ± 1.4%) compared to other treatments (P<0.05). Salinity is the most suitable for incubation of fertilized eggs of mouse grouper from 30 to 35‰ with high hatching rate of 83.4 - 85.6% and low deformity rate of 1.65 - 1.73% in comparision with other treatments (P<0.05). In conclusion, among the range of temperature and salinity studied, mouse grouper eggs reached highest incubation performance at 28ºC and salinity ranged from 32 to 35‰.

Besides observing the signs of clinical manifestations of 200 sows infected with metritis-mastitis-agalactia (M.M.A) syndrome in four provinces representative of the Red River delta in Vietnam, this study also investigated the hematological and biochemical parameters for comparison with clinically healthy sows. The research results showed that the clinical signs of sow group with M.M.A syndrome were similar to the manifestations of Pyrexia, restlessness, and anorexia The sows metritis-mastitis-agalactia (M.M.A) syndrome were not willing for the piglets to suckle or exhibited a marked disinterest in the piglets. The blood physiological and biochemical parameters indicated that the hematological indicators, such as number of red blood cells, hemoglobin concentration, corpuscular volume, corpuscular hemoglobin and corpuscular hemoglobin concentration of blood of sows with M.M.A syndrome group were higher than those from healthy sow group (P <0.05). In comparison with healthy sows, the number of white blood cell and neutrophils rate in blood of sows with M.M.A syndrome were higher. On the contrary, the rate of other types of white blood cells were lower (P <0.05). Albumin, total protein and β-globulin in the serum of sows with M.M.A syndrome group were lower than those in the blood of control sow group, whereas serum α - globulin và γ-globulin concentrations were higher. In addition, glicemia of M.M.A syndrome sows was decreasing, while enzymatic parameters (GOT and GPT activity) were increasing in comparison with the control group.

Coffee production plays an important role in the economic structure of Krong Nang district. Total area of coffee production in Krong Nang district amounts to 26,013 ha, of which 25,662 ha are in the harvesting period, accounting for 13.45% of total area under coffee in Dak Lak province. More than 80% coffee acreage in the district is cultivated on basaltic soils and coffee is considered as the highest economic crop in Krong Nang district. Survey results showed that the coffee farming households could be divided into three groups: the high economic efficiency group occupied around 20% total surveyed households with average coffee yield of 4.3 tons per ha and net profit of VND 99.91 million per ha; the medium and low economic efficiency groups ocupied 44% and 36% of total surveyed households, with yield of 3.05 tons and 1.85 tons per ha, and profit of 69.8 million VND and 37.34 million VND per ha per year, respectively.

The paper assessed the current status of the major environmental factors and indicators in the border gate economic zone at Cau Treo in order to select the environmental factors for integration to land use planning in Cau Treo economic zone. The results showed that the enviromental indicatos of surface water and underground water are within the permissive limit in accordance with the standards QCVN 08: 2008/BTNMT; the indicators of air quality and noise satisfy the standards QCVN 05:2009. This Economic Zone is located in areas of frequent occurrence of floods, waterlogging and land slides leading to severe loss and soil degradation due to erosion,. The forest and fauna are well protected with rather high vegetation coverage and species diversity, however, the quality severely declines.

The study aims at analyzing the nature of residential areas of Hoang Hoa district in response to “Tam nong” policy. The data were gathered from 420 residential areas of the district. The results showed that the district has a population of 248,152 people, 63,004 households, and a total area of 22,473.18 hectares. The land alloeted to residential areas is 6,470.56 hectares, including 1,965.53 hectares for housing (30,38%). The district consists of 49 communes with 420 residential areas. On average, each commune has 15 residential areas and each residential area includes 591 people and 150 households. The classification of residental areas was based on criteria specified in Vietam’s Standards No. 4418 in 1987 and National Criteria for Renewing Rural Areas in Decision No. 491/QD-TTg. As a result, 420 residential areas of Hoang Hoa were classified into 3 levels: level 1 with 135; level 2 with 233; and level 3 with 52 residential areas. By 2020, the system of residential areas will develop into 4 regions according to their developmental characteristics.

The study evaluated the curent status of agricultural land use models as well as economic effectiveness of land use types TheGAMS multipurpose mathematic model was used to determine land use typeswith high economic efficiency to serve as basis for developing land use guidelines until 2020 in Tu Ky district. In 2010, there were 29 land use formswithin three main land use types in the district. The economic efficiency of land use for rice cultivation was shown to be lower that land use for non-rice crops. Based on GAMS model with varying food production and investemnt as variables, potential land use types were proposed.

The soil of Thach That district, Hanoi city is divided into 4 soil groups with 8 soil types. The yellowish red soil group occupies the largest area with 6,033.71ha, accounting for 32.69% of total natural area. The Fluvisols group occupies the 2nd largest area wiith 3,670.82ha or 19.89 % of total natural area. The swampy soil and peat soil group, and deposit valley soil group have lowest area with 0.25% and 0.19% of total natural area of the district, respectively.The texture of yellowish red soil group varies from sandy loam to light clay and from slightly acidic to very acidic. CEC varies from low to medium. The content of total and available nutrients is quite high in the top soil layer but lower in subsoil layers. The Fluvisols group’s reaction is from mederately acidic to slightly acidic; the soil nutrient content varies from medium to quite rich in the top soil layer. CEC and exchangeable bases ranges from medium to quite high. The swampy soil and peat soil group has strong gley layer; the soil structure is destroyed, soil pH is from acidic to very acidic. The soil nutrient content varies from quite high to high. The deposit valley soil group varies from acidic to very acidic. Soil nutrient content, CEC and exchangeable base content are low, soil texture varies from light loam to medium loam.

Nam Dinh province is located at the South of the Red River Delta, with total natural area of 165,146 ha. Nam Dinh owns advantages in marine economy, but climate change and sea-level rise significantly influence the land use of the province. Based on current situation on land use, land potentials, land use models, climate change, sea-level rise scenarios by the year 2020 were conducted. The results are showed that agricultural land area is estimated to remain at 103,479.97ha, non-agricultural land area at 62,109.84ha, and unused land area at 2,552.55ha. To adapt to climate change, the coastal areas should be encouraged to adopt such land use patterns which not only focus on land use for farming but also link land use towards service-goods, such as aquaculture and eco-tourism.

Trophic Diatom Index (TDI) first suggested by Kelly and Whitton in 1995 is an index assessing status of organic nutrients in aquatic ecosystems which bases on the total of diatom species and individuals that indicate the eutrophication. This study used TDI values to evaluate nutrient situation in the sediment at Can Gio Mangrove Biosphere Reserver after Durian typhoon (December 6, 2006). The study analyzed 72 soil samples and 108 diatom samples in the sediment for two seasons. Analysis of variance (ANOVA) showed that in the rainy season the mean TDI was significantly different between three sites: non-forest, mix and forest (F=10.88; P=0.0012). In contrast, in dry season, the mean TDI was not significantly different between three sites (F=0.45; P=0.65). We found species Achnanthidium minutissimum which is indicative of low total phosphorus and species Luticola goeppertiana, Navicula recens indicating high total phosphorus. However, we did not find correlation between the mean TDI and the total phosphorus and total nitrogen in the study. The studies on percent tolerant valves and orthophosphate concentration may help clearly explain about the relationship between the TDI and total phophorus and total nitrogen concentrations.

The sustainable land use management relates to the current and future areas of economics, society, culture and environment, limits land and water degradation and reduces production costs. The study aims to find out some factors which have effects on the management of agricultural land use in SonTay Town. The impact of the factors on the management of agricultural land use was analyzed by using Kruskal-Wallis test and Spearman Rank Corrrelation Coefficient in SPSS15.0 with significant level: 0.05 through the investigation of 160 households from 4 communes and 30 office workers. The results of the research show that the local people realise that there has been a remarkable change in the land use management over the period and the main factors which influence the management of agricultural land use are land policies, policies supporting capital, techniques; characteristic of land, scale of the area of farm land, and the role of media and information.

In continuously variable transmission, accurate control ofgear ratios matchingwell with loading conditions is of crucial importantance. There are many methods of control, of which control by hydrostatic hydraulic system is considered as an optimal choice. Electricity – hydraulics transmission is characterized by the ability to transmit large forces, adjust the position control accuracy and automation capabilities. This article reportsthe resultsof modeling and simulation control systems, adjusting the position to control the ratio of V-belt variator using electricity – hydraulics system by servo valve.

Research on rice harvesters/combiners towards particle separation and the short straw chopped into short segments to efficiently exploit post-harvest straw has been carried out in recent years at the Faculty of Engineering, Hanoi University of Agriculture. Principles of structure and model of straw chopping machine was presented. In this study, the authors provieded additional research and experimentation results of single element parameters affecting the cutting quality and cutting energy cost for operation of chopping straws. The findings can serve as the basis for studying multiple factors to find optimal parameters. Research showed the effect domain of cutting speed v(m/s), the supply quantity q(kg/s) and clamp angle (degrees) on the quality of cut x(%) and the specific energy costs Ne(kW.s/kg).

The information systems help users backup and process information. However, some reasons of apdating backup information having redundant attributes make it difficult for exploring knowledge. Thus, the attribute reductions are essential requirements for mining knowledge. There exist several types of attribute reduction and decision rules that have been proposed in data mining. The present paper described a heuristic algorithm to find the reduction on decision table based on the discernibility matrix.

Nowadays, livestock develops in the direction of combining industrial livestock husbandry with traditional livestock keeping (household) under an appropriate scale which is much larger than the that in the past time period. This not only requires suitable animal feed processing machines in general but also suitable feed mixers in particular. 50kg-per-batch feed mixer can be used to mix various types of feed. Moreover, this type of equipment is easy to fabricate, install, remove and clean. The machine is suitable for farm economic models, small-scale or household level. The machine can be used to blend feed from the raw crushed materials (natural origin), or concentrate feed with locally available raw materials at the request of the producer.

The share of agricultural GDP of the total GDP of Nghe An Province is relatively high. Agriculture plays a decisive role in the stablization and development of the province. Furthermore, the added value of livestock sector has a tendency to grow faster than that of cultivation; this is in accordance with the general trend of the social economic development and the target of economic structure of Nghe An. This study was conducted in order to recommend economic policy in the coming years for the agricultural production, especially livestock and pig sectors of Nghe An. The research findings indicated that major marketing actors play an important role in the process of production and distribution of pork products. Among the actors, producers face relatively high risk while slaughters and retailers have a high benefit in comparison with other actors. A set of measures should be taken for improvement of distribution channels of pork in Nghe An.

The global financial and economic crisis, which was triggered by the Lehman Brothers shock in September 2008, has had enormous negative impacts on the global economy and Vietnam. In this paper, some gravity models were constructed using the Hausman–Taylor (1981) estimator, Fixed-effects (FE), Random-effects (RE) estimations, and applied to recent panel data that includes 18 of Vietnam’s major trade partners during the period from 1995 to 2011. This purpose was to examine the possible impacts of the 2008 global financial and economic crisis on the export and import of Vietnam. The authors found evidence broadly consistent with the prediction that the crisis strongly reduced the country’s import. By contrast, there was no evidence that demonstrated convincingly that this crisis decreased the country’s export. In addition, the authors modeled and found the reciprocal relationship between the export and import of Vietnam.